Various preparation methods which could control dissolution of a pesticidal active ingredient have been heretofore studied aiming at phytotoxicity reduction and efficacy sustainability of a granular pesticide preparation containing a pesticidal active ingredient. For example, methods of blending paraffin wax, thermoplastic resin, activated carbon, foam granules or clay mineral in combination to attain sustained-releasability were proposed (See Japanese Patent Laid-Open No. 63-35504, Japanese Patent Laid-Open No. 63-45201 and Japanese Patent Laid-Open No. 2-288803).
However, such conventional methods for sustained-releasability were not necessarily effective and had such problems that the preparation procedure of a granular pesticide preparation was complicated and that release of the pesticidal composition was insufficient and most of the pesticidal active ingredient was not utilized and left intact in the pesticidal composition so that pesticidal active ingredients more than required would be released to the environment to result in causing a problem that the burden on the environment was significant.
A production method of a granular pesticide preparation comprising preparing an inner core and coating the inner core with an active ingredient different from that of the inner core has been also proposed aiming at stabilization of different active ingredients (See Japanese Patent Laid-Open No. 9-315903), but technique to control, in a single pesticide preparation, a pesticidal active ingredient for which sustained-releasability is necessary and a pesticidal active ingredient for which prompt release from the pesticide preparation is desired has not yet been established.